Studies of scattering processes in scalar models with two Higgs doublets have recently hinted at a connection between the absence of flavor-space entanglement in ${\mathrm{\Phi }}^{+}{\mathrm{\Phi }}^0$ scattering and an emergent SO(8) symmetry in the scalar potential. We extend the analysis to all scattering channels with two particles in the external states by treating the process as a four-qubit system in the weak isospin and flavor subspaces of the two-particle state. We work with a generic quantum-information-theoretic principle encoded by the commutativity of the initial-state density matrix with the transition matrix (at leading order in perturbation theory). This yields a special case of the entanglement minimization conditions previously derived in the literature, and we interpret the principle in terms of the conservation of nonstabilizerness (or “magic”). Working at leading order in the quartic couplings, we find a consistent set of conditions that implies an SO(8) symmetry on the quartic part of the potential for scattering an arbitrary initial state but a smaller $\mathrm{SU}(2{)}_R$ symmetry when the initial state is chosen to have definite isospin. This follows by accounting for Bose symmetry in the initial state, which introduces entanglement between the isospin and flavor subspaces.

A comprehensive analysis of the photoproduction of $J/\mathrm{\Psi }$ and $\mathrm{\Upsilon }$ mesons in peripheral $PbPb$ collisions at the center-of-mass energies of the Large Hadron Collider is performed, considering distinct assumptions for the modeling of the nuclear photon flux, photon-nucleus cross section, overlap function, and dipole-proton scattering amplitude. The comparison of these predictions with the ALICE data is also performed. Our results indicate that a detailed analysis of the production of both mesons will be very useful to improve the description of photon-induced processes in peripheral collisions.

A search for flavor-changing neutral current interactions of the top quark ($t$) and the Higgs boson ($H$) is presented. The search is based on proton-proton collision data collected in 2016–2018 at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$. Events containing a pair of leptons with the same-sign electric charge and at least one jet are considered. The results are used to constrain the branching fraction ($\mathcal{B}$) of the top quark decaying to a Higgs boson and an up ($u$) or charm ($c$) quark. No significant excess above the estimated background was found. The observed (expected) upper limits at a 95% confidence level are found to be 0.072% (0.059%) for $\mathcal{B}(t\to Hu)$ and 0.043% (0.062%) for $\mathcal{B}(t\to Hc)$. These results are combined with two other searches performed by the CMS Collaboration for flavor-changing neutral current interactions of top quarks and Higgs bosons in final states where the Higgs boson decays to either a pair of photons or a pair of bottom quarks. The resulting observed (expected) upper limits at the 95% confidence level are 0.019% (0.027%) for $\mathcal{B}(t\to Hu)$ and 0.037% (0.035%) for $\mathcal{B}(t\to Hc)$.

A partial-wave analysis is performed on the decay $J/\psi \to \gamma {\pi }^0{\pi }^0{\pi }^0$ within the ${\pi }^0{\pi }^0{\pi }^0$ invariant-mass region below $1.6\mathrm{GeV}/c^2$, using $(10.09\pm 0.04)\times {10}^9$ $J/\psi$ events collected with the BESIII detector. Significant isospin-violating decays of $\eta (1405)$ and $f_1(1420)$ into $f_0(980){\pi }^0$ are observed. For the first time, three axial vectors, $f_1(1285)$, $f_1(1420)$, and $f_1(1510)$, are observed to decay into ${\pi }^0{\pi }^0{\pi }^0$. The product branching fractions of these resonances are reported.

We report measurements of $\mathrm{\Upsilon }(1S)$, $\mathrm{\Upsilon }(2S)$ and $\mathrm{\Upsilon }(3S)$ production in $p+p$ collisions at $\sqrt{s}=500\mathrm{GeV}$ by the STAR experiment in year 2011, corresponding to an integrated luminosity ${\mathcal{L}}_{\mathrm{int}}=13{\mathrm{pb}}^{-1}$. The results provide precise cross sections, transverse momentum ($p_{\mathrm{T}}$) and rapidity ($y$) spectra, as well as cross section ratios for $p_{\mathrm{T}}<10\mathrm{GeV}/\mathrm{c}$ and $|y|<1$. The dependence of the $\mathrm{\Upsilon }$ yield on charged particle multiplicity has also been measured, offering new insights into the mechanisms of quarkonium production. The data are compared to various theoretical models: the color evaporation model (CEM) accurately describes the $\mathrm{\Upsilon }(1S)$ production, while the color glass $\mathrm{condensate}+\text{nonrelativistic}$ quantum chromodynamics ($\mathrm{CGC}+\mathrm{NRQCD}$) model overestimates the data, particularly at low $p_{\mathrm{T}}$. Conversely, the color singlet model (CSM) underestimates the rapidity dependence. These discrepancies highlight the need for further development in understanding the production dynamics of heavy quarkonia in high-energy hadronic collisions. The trend in the multiplicity dependence is consistent with CGC/saturation and string percolation models or $\mathrm{\Upsilon }$ production happening in multiple parton interactions modeled by pythia8.

We present a numerical relativity study of the accretion properties of a nonspinning black hole in a cosmology driven by a scalar field. The simulations are carried out with a modified moving-puncture gauge condition suitable for cosmological space-times. We considered a scalar field with potential $V=\lambda {\phi }^4/4$ and derived the black hole mass growth formula for this scenario using the dynamical horizon framework. As with perturbative studies, we find that the accretion rate $\dot{M}\propto M^2$, with $M$ the mass of the black hole, and that $\dot{M}\propto {\dot{\phi }}^2$. We verify that the results of the simulations satisfy the mass growth formula. Unexpectedly, the scalar field dynamics in the neighborhood of the black hole is not significantly different from the behavior of the field far away from the hole. We found situations where the black hole can grow $\sim 15\%$ of its initial mass before the scalar field reaches the bottom of its potential.

Starting from the recently derived conservative tail-of-tail action [High precision black hole scattering: Tutti Frutti vs worldline effective field theory, arXiv:2504.20204.] we compute several dynamical observables of binary systems (Delaunay Hamiltonian, scattering angle), at the 6.5 post-Newtonian accuracy and up to the eighth post-Minkowskian order. We find perfect agreement with previous self-force results, and (when inserting a recent high-post-Newtonian order derivation of radiated angular momentum [Scattering of a point mass by a Schwarzschild black hole: Radiated energy and angular momentum, arXiv:2507.03442.]) with state-of-the-art post-Minkowskian scattering results [Emergence of Calabi–Yau manifolds in high-precision black-hole scattering, Nature (London) 641, 603 (2025).].

In addition to curvature singularities, electrovacuum black holes in general relativity exhibit thermodynamic singularities. These so-called Davies’ points occur at nonextremal values of charge and spin where the heat capacity diverges and may indicate a type of theoretical incompleteness. The thermodynamic regularity of several families of static, asymptotically flat spacetimes with bounded curvature invariants is examined using a theory-agnostic framework, showing that, while they may be regular in physical space, they are generally not in phase space. The inclusion of angular momentum, via the Newman-Janis algorithm, makes the set of such “doubly regular” objects especially restrictive. It is argued that, if thermodynamic regularity is to be considered a desirable property for an astrophysical black hole, these considerations could be used to narrow down the viable pool of regular extensions to the Kerr-Newman metric.

This paper explores the electromagnetic Penrose process and fundamental frequencies with Einstein-Euler-Heisenberg theory with including new dimensionless parameter $\beta$. This parameter was related to the fine structure constant $\alpha$ and the Schwinger critical field and the BH mass parameter ($M$). The results of our research showed that the energy efficiency in the electromagnetic Penrose process can reach $>100\%$ in some cases, it has 25% energy efficiency in the case when a falling particle has no charge. However, the Christodoulou-Ruffini-Hawking theory can limit these values. In all results, we observed a decrease in energy efficiency when the value of the parameter $\beta$ was increased. By checking how harmonic oscillations depend on $\beta$, we observed that horizontal oscillations decrease and vertical oscillations increase when we consider $\beta$. We plotted horizon, ISCO orbits, effective potential structures, extractable energy, conservation energy, and angular momentum with Keplerian frequency and quasiperiodic oscillations.

Clusters of galaxies trace massive dark matter halos in the Universe, but they can include multiple halos projected along lines of sight. As a case study, we quantify the properties of halos contributing to clusters identified by the redMaPPer algorithm using the Cardinal simulation, which mimics the Dark Energy Survey data. For each cluster, we identify the halos hosting its member galaxies, and we define the main halo as the one contributing the most to the cluster’s richness ($\lambda$, the estimated number of member galaxies). At $z=0.3$, for clusters with $\lambda >60$, the main halo typically contributes to 92% of the richness, and this fraction drops to 67% for $\lambda \approx 20$. Defining “clean” clusters as those with $\ge 50\%$ of the richness contributed by the main halo, we find that 100% of the $\lambda >60$ clusters are clean, while 73% of the $\lambda \approx 20$ clusters are clean. Three halos can usually account for more than 80% of the richness of a cluster. The main halos associated with redMaPPer clusters have a completeness ranging from 98% at virial mass ${10}^{14.6}{h}^{-1}{M}_{\odot }$ to 64% at ${10}^{14}{h}^{-1}{M}_{\odot }$. In addition, we compare the inferred cluster centers with true halo centers, finding that 30% of the clusters are miscentered with a mean offset 40% of the cluster radii, in agreement with recent X-ray studies. These systematics worsen as redshift increases, but we expect that upcoming surveys extending to longer wavelengths will improve the cluster finding at high redshifts. Our results affirm the robustness of the redMaPPer algorithm and provide a framework for benchmarking other cluster-finding strategies.

We present a high-quality, homogeneous sample of 157 $\mathrm{H}\beta$ reverberation-mapped active galactic nuclei (AGNs) spanning redshifts $0.00308\le z\le 0.8429$, which is approximately 3.8 times larger than the previously available high-quality homogeneous sample. Using the broad-line region radius-luminosity relation ($R-L$), which involves the broad $\mathrm{H}\beta$ line time delay and the monochromatic luminosity at 5100 Å, we show that the sample is standardizable by using six spatially flat and nonflat cosmological models. The inferred cosmological model parameters are consistent within $2\sigma$ uncertainties with those from better established baryon acoustic oscillation and Hubble parameter measurements, with the exception of two nonflat models that are ruled out by other data. The $R-L$ relation slope is found to be flatter ($\gamma =0.428\pm 0.025$ in the flat $\mathrm{\Lambda }\mathrm{CDM}$ model) than the slope of 0.5 expected from a simple photoionization model as well as the slope found previously for the smaller homogeneous sample. In addition, we find a mild dependence of $\mathrm{H}\beta$ $R-L$ relation parameters as well as its intrinsic scatter on the Eddington ratio by comparing the $R-L$ relations for low- and high-accreting equal-sized subsamples. A future analysis of a larger homogeneous sample containing a broader range of luminosities and Eddington ratios is necessary to confirm the standardizability of $\mathrm{H}\beta$ AGNs.

Investigations of trajectories of various objects orbiting the Milky Way (MW) halo with modern precision, achievable in observations by Gaia, requires sophisticated, nonstationary models of the Galactic potential. In this paper we analyze the evolution of the spherical harmonics expansion of MW analogs potential in constrained simulations of the Local Group (LG) from the HESTIA suite. We find that at distances $r\ge 100\mathrm{kpc}$, the nonspherical part of the potential demonstrates a significant impact of the environment: ignoring the mass distribution outside the virial radius of the MW results in $>20\%$ errors in the potential quadrupole at these distances. Account of the environment results in a noticeable change of the angular momenta of objects orbiting MW analogs. Spherical harmonics vary significantly during the last 6 Gyr. We attribute variations of the potential at $r\ge 30\mathrm{kpc}$ to the motions of MW satellites and LG galaxies. We also predict that the nonsphericity of the real MW potential should grow with distance in the range $r_{\mathrm{vir}}<r<500\mathrm{kpc}$, since all realizations of simulated MW-like objects demonstrate such a trend.

Different cosmological probes, such as primary cosmic microwave background (CMB) anisotropies, CMB lensing, and cosmic shear, are sensitive to the primordial power spectrum (PPS) over different ranges of wave numbers. In this paper, we combine the cosmic shear two-point correlation functions measured from the Subaru Hyper Suprime-Cam (HSC) Year 3 data with the Planck CMB data, and the ACT DR6 CMB lensing data to test modified shapes of the PPS at small scales, while fixing the background cosmology to the flat $\mathrm{\Lambda }\mathrm{CDM}$ model. We consider various types of modifications to the PPS shape: the model with a running spectral index, the tanh-shaped model, the Starobinsky-type modification due to a sharp change in the inflaton potential, the broken power law model, and the multiple broken power law model. Although the HSC cosmic shear data is sensitive to the PPS at small scales, we find that the combined data remains consistent with the standard power law PPS, i.e., the single power law model, for the flat $\mathrm{\Lambda }\mathrm{CDM}$ background. In other words, we conclude that the $S_8$ tension cannot be easily resolved by modifying the PPS within the $\mathrm{\Lambda }\mathrm{CDM}$ background.

Recently, there has been considerable debate regarding potential evidence for the dynamical nature of dark energy, particularly in light of baryon acoustic oscillation measurements released by the Dark Energy Spectroscopic Instrument (DESI) survey. In this work, we propose an agnostic test that simultaneously constrains the dark energy equation of state and probes the possibility of a transition between the quintessence and phantom regimes, or vice versa. Our initial approach is independent of physical priors, allowing the data to determine which behavior best fits the parameters. We then consider a minimally modified gravity theory known as VCDM, into which we can map our initial approximation, placing it within a theoretically stable framework. To this end, we incorporate the most up-to-date data sets available, including baryon acoustic oscillation measurements from DESI-DR2, type Ia supernovae from the PantheonPlus, DESY5, and Union3 samples, and cosmic microwave background data from Planck. Our analysis reveals strong and statistically significant evidence for a quintessence-phantom transition across various data combinations. The strongest evidence is found for Planck$+\mathrm{DESI}+\mathrm{DESY}5$, with a significance exceeding $\sim 5\sigma$ in favor of a quintessence-phantom transition at $z_{†}=0.493_{-0.081}^{+0.063}$. Beyond this redshift, the equation of state remains within the phantom regime, while for $z<z_{†}$, it favors the quintessence regime. Despite this strong indication, we find that such transitions do not resolve the $H_0$ tension.

Double neutron star (DNS) systems could serve as intriguing dual-line gravitational-wave (GW) sources, emitting both high- and low-frequency GWs, arising respectively from the asymmetric spinning bodies of individual neutron stars (NSs) and the binary orbital inspiral. Detecting such dual-line signals could provide novel perspectives on binary orbital geometry and NS internal physics. We expand upon previously calculated spinning NS waveforms by incorporating higher-order terms of NS structural parameters. A population simulation is performed for spinning NS components in DNS systems potentially detectable by the space-based Laser Interferometer Space Antenna (LISA). Based on 4-yr LISA observation of 35 resolvable DNS systems under an optimistic scenario, we estimate that 6 (22) spinning NS components could be detected by the next-generation ground-based GW detector, Cosmic Explorer, under log-uniform (uniform) sampling of NS structural parameters. For these dual-line sources, the median signal-to-noise ratio achievable with Cosmic Explorer is approximately 20–30. Through the dual-line GW detection strategy, the relative measurement accuracy of the NS moment of inertia is estimated to be $\sim 8\%$.

Galactic cosmic rays (CRs) generally share common propagation features, leading to consistent spectral observations of secondary nuclei such as Li, Be, and B. However, the Li spectrum predicted by the CR diffusion coefficient inferred from B/C is significantly lower than the latest measurement of AMS-02. This anomaly may be attributed to the missing contributions from the heavy nuclei components in cosmic rays. By including these missing contributions the excess of the Li spectrum disappears. However, another inconsistency still exists since the calculated Li spectrum is now overestimated compared to the data. In this work, we update the cross-section model used to calculate the Li production according to more cross-section measurements. We find that the cross sections of these added reactions are systematically overestimated, and should be renormalized to the interpolations of available data. As a result, our prediction of the total Li spectrum is consistent with the measurement without discrepancy, and our prediction of the ${}^6\text{Li}$ and ${}^7\text{Li}$ spectra are consistent with the preliminary measurements of AMS-02 within the cross-section uncertainties.

We study a new channel for binary system formation involving stars and stellar-mass primordial black holes (PBHs) embedded in dark matter (DM) minihalos. In this scenario, binaries form when a star passes through the DM minihalo surrounding a PBH and loses sufficient energy due to dynamical friction. The continued energy loss induced by this friction is expected to drive the resulting systems to merge rapidly. We estimate their merger rate and explore the implications for two observables: rapidly decaying X-ray binaries in the Milky Way and gravitational waves sourced by compact object mergers. We find that, for a PBH abundance ${\mathrm{\Omega }}_{\mathrm{PBH}}/{\mathrm{\Omega }}_{\mathrm{DM}}=0.01$, this mechanism naturally produces a population of $\mathcal{O}(1)$ currently observable short-lived X-ray binaries. It also leads to a non-negligible gravitational wave event rate of $\mathcal{O}(0.3){\mathrm{Gpc}}^{-3}{\mathrm{yr}}^{-1}$, potentially involving high mass ratios and black holes in the lower or upper mass gap. Notably, most mergers arise in low-mass galaxies, making the latter rate sensitive to the low-mass end of the galaxy stellar mass function. The dynamical friction channel thus offers a plausible explanation for several unusual observations reported in recent years across both the X-ray and gravitational wave domains.

Extreme gravitational lensing and relativistic frequency shifts, combined together, imply that radiation emitted from a black hole’s vicinity can echo at different frequencies and times, leading to spectrotemporal correlations in observed signals. If such correlations are uncovered by future observations, they could provide a probe of the spacetime geometry in the strong-field region near black holes. Here, motivated by these prospects, we numerically compute the two-point correlation function of specific flux fluctuations in a simple model of line emission by a hot spot in an equatorial circular orbit. We make use of the adaptive analytical ray tracing (aart) code to generate the light curves we then correlate. Our results for the correlation maps show a clear decomposition into direct emission-dominated, and lensing-dominated contributions. The computation transcends past analytical approximations, studying the main contribution to the correlation function, which is not deep in the universal regime. We compute correlation maps for many combinations of black hole mass, spin, inclination, hot spot width, and orbital radius, and study their dependence on these parameters. The correlation maps are then used to train convolutional neural networks which can be used to estimate source parameters, achieving promisingly low evaluation errors within the model. Our results could be relevant for future x-ray spectroscopic missions, offering insights into black hole parameter inference.

The interaction of ultrahigh-energy cosmic rays with air nuclei triggers extensive air showers that reach their maximal energy deposition at the atmospheric depth $X_{\max }$. The distribution of this shower observable encodes information about the proton-air cross-section via fluctuations of the primary interaction point, $X_1$, and hadron production through $\mathrm{\Delta }{X}_{\max }\equiv X_{\max }-X_1$. We introduce new multiparticle production variables, ${\alpha }_{\mathrm{had}}$, ${\zeta }_{\mathrm{had}}$, and ${\zeta }_{\mathrm{EM}}$, built from the energy spectra of secondaries in the primary interaction. Their linear combination, $\xi$, predicts over 50% of the fluctuations in $\mathrm{\Delta }{X}_{\max }$. Moreover, we build a probabilistic mapping based on the causal connection between $\xi$ and $\mathrm{\Delta }{X}_{\max }$ that enables model-independent predictions of $X_{\max }$ moments with biases below $3\mathrm{g}\mathrm{c}{\mathrm{m}}^{-2}$. Therefore, measurements of the distribution of $X_{\max }$ allow the probing of secondary hadron spectra from the cosmic-ray-air interaction, in proton-induced showers. The distributions of the new multiparticle production variables can be measured in rapidity regions accessible to current accelerators and are strongly dependent on the hadronic interaction model in the kinematic regions exclusive to ultrahigh-energy cosmic rays.

We investigate key methodologies of Bhatnagar-Gross-Krook subgrid modeling for neutrino fast flavor conversions (FFCs) in core-collapse supernova based on spherically symmetric Boltzmann radiation hydrodynamics simulations. We first examine time integration methods (explicit, implicit, or semi-implicit) and time step control for the subgrid term and then compare various approaches in the literature approximating FFCs in two aspects: (i) angular-dependent survival probability of neutrinos versus simple equipartition condition with a certain baryon mass density threshold and (ii) four-species treatment versus three-species assumption (${\nu }_x={\overline{\nu }}_x$). We find that the equipartition condition is reasonable for outgoing neutrinos, but large deviations emerge in the ingoing neutrinos, that has an influence on matter profiles. We also find that the three-species model, in which flavor conversions evolve toward erasing electron neutrino lepton number crossings, behave differently from the four-species models, where heavy leptonic neutrino numbers are appropriately treated in FFC subgrid modeling. In four-species models, we commonly observe noticeable differences between ${\nu }_x$ and ${\overline{\nu }}_x$, highlighting the limitation in three-species treatments to study impacts of flavor conversion on neutrino signals. Our result also suggests that FFC models yield lower neutrino heating rate and smaller shock radii compared to cases with no FFC, in agreement with earlier studies employing quantum kinetic neutrino transport. This work provides valuable information toward robust implementation of FFC subgrid model into classical transport and serves as a pilot study for future multidimensional simulations.